With the increase of manpower cost, there is an urgent need for automatic production in low-pressure cast aluminum wheel industry, the production flow of low-pressure cast wheels is as follows: smelting →low-pressure casting→moving to runner→heat treatment→machining→coating→packaging and delivery. As the casting tolerance of cast wheel blanks is generally ±0 .9 mm, and is random to a certain extent, while the dimension of cap groove of wheel products depends on the cast surface in combination with the machined surface, and the tolerance has strict requirement, and is generally ±0 .25 mm, if the cast wheel blank from heat treatment is directly delivered using the stream roller way to the automatic machining unit for machining, the dimension of the cast blank within the tolerance range is random, as a result, the cap groove dimension that depends on the combination of the cast surface and the machined surface is extremely poor, causing low acceptability rate of wheel machined products and the increase of manufacturing cost.